TECHLONE JANUARY 1998 pg1

Volume 2 I Issue I January 1998

This is your column. It contains the best and most frequently asked questions regarding
Auto Glass Replacement. If you have any comments or ideas that you’d like to share,
contact your local Libbey-Owens-Ford Co. representative.

Is glass considered a liquid or a solid?
Believe it or not, glass is amorphous (non crystalline) and is considered a liquid. When
glass is in its “hardened” phase, it has a VERY slow moving flow. You may see an
example of this in very old houses with original plate glass. Old houses have window
panes that measure thicker at the bottom than at the top. Glass as we know and work
with it is actually in its super cooled liquid phase.

Does glass ever become a solid?
Yes, glass can crystallize and become solid. For solidification of glass to occur naturally, it takes 70 million years for this to happen. Solidification can be accelerated by other
means such as how the glass melt is cooled or if its chemical state is altered slightly
enough to change the phase of the melt. An example of crystalline glass can be found on
the inside surface of an insulated glass (IG) unit that appears to be stained. The
crystalline glass has an opaque milky white or “frosted” appearance. It forms in the
presence of moisture that gets trapped in the lG unit. The moisture reacts with the inside
surface of glass causing the sodium to leach out of the glass. The absence of sodium
changes the melt enough to promote crystallization of the glass. What appears to be
stained glass, is actually glass in the solid state!

What is the difference between the DQ8425 and DQ9195?
The difference is in the latch assembly for these parts. These are both swing-out rear
quarter windows for the Chevy/GMC ST light pickup. The DQ8425 fits the standard two
door model. The DQ8425 latch assembly is a common straight latch. The DQ9195 fits
the new t~’iee door pickup which is also known as the Highlander model. The latch
assembly on the DQ9195 is curved. The curved latch assembly will allow the swing-out to
open wider so that it will not interfere with the function of the door.